Generally, airbags are deployed to prevent injury of passengers upon crash of vehicles, which include front airbags including a driver airbag and a passenger airbag and a side (curtain) airbag that is deployed upon a side crash.
Referring to FIG. 1, an airbag deploying system includes a front crash sensor 16 disposed on a vehicle bumper, i.e., a side member or Front End Module (FEM) to sense a front crash with an acceleration signal. A side crash sensor 12 is disposed on a side part of a vehicle body to sense a side crash with an acceleration signal, and a side pressure sensor 14 senses the side crash with a pressure signal. An airbag control unit 10 controls the deploying of a driver airbag 30 or a passenger airbag 32 based on the sensed signal of the front crash sensor 16, or controls the deploying of a side airbag based on the sensed signals of the side crash sensor 12 and the side pressure sensor 14.
In this case, the front crash sensor 16 and the side crash sensor 12 are not separately provided but are mounted in the airbag control unit 10 to sense an acceleration of longitudinal direction (ACU-X) and a lateral direction (ACU-Y).
Accordingly, based on signals of the side pressure sensor 14, the front crash sensor 16, and the side crash sensor 12, the airbag control unit 10 controls the deploying of the driver airbag 30, the passenger airbag 32, or the side airbag.
When the sensed signal ACU-Y (the thick line in FIG. 2A) of the airbag control unit is larger than a threshold (the dotted line in FIG. 2A), and the sensed signal (SIS LH Y) of the side crash sensor, or the sensed signal (the thick line in FIG. 2B) of the side pressure sensor is larger than a threshold (the dotted line in FIG. 2B), the side airbag is deployed at a certain deploying point (TFIRE).
Although this airbag deploying system is mounted in a vehicle, due to a small magnitude of signals sensed from local crashes of various angles and speeds from actual crash accidents, the side airbag may not be deployed, thus causing damage or an injury to a vehicle body and a passenger.
In other words, since a direct impact is not applied in a lateral direction of a vehicle body in case of local front crashes occurring at various angles, the sensed signal ACU-Y of a side airbag control unit and the sensed signal values of the side crash sensor and the side pressure sensor are indicated as signal values (thin lines in FIGS. 2A and 2B) that cannot exceed the threshold. In spite of a situation in which the side airbag in addition to the front airbag needs to be deployed, the side airbag may not be deployed, thus causing deformation of a vehicle body and injury of passengers.
Thus, in the typical airbag deploying system, upon local front crashes at various angles, although both front and side airbags need to be deployed to protect passengers, only the front airbag is deployed by sensing an X-direction (traveling direction) of the vehicle. In this case, since a direction impact is not applied in the lateral direction of the vehicle body, the sensed values of the Y-direction acceleration and pressure do not exceed a predetermined threshold, making it impossible to deploy the side airbag, and thus causing deformation of the vehicle body and injury of passengers.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure, and therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.